What is the widest tire anyone has put on the stock 18" rims. According to Big Custom Wheels website, it shows that a 285/40/18 will fit a 18x8.5 wheel. Is this correct? Has anyone tried this? A 285 seems a bit wide for a 8.5 wheel to me, but it would be nice if it would fit.

 

Interested here as well !

 

Test on this page:
http://www.1010tires.com/TireSizeCalculator.asp

You'll see that with 285 tire you need a 9.5 to 11" rim width

 

People who autocross put 285/40/18 on a 18x8.5 rims. It has stood the test of extreme use. Go for it!

 

Her is a link that I saw the recommended tire size on. The site is Big Custom Wheels. They recommend a 8.5 to 10.5 for a 285/40/18. Is this incorrect?


http://www.bigcustomwheels.com/rt_ti...eter=18&brand=

 

You would be good with a 275 and I think 285 is a little overboard but can still be done safely its just pushing the boundaries.

 

Check www.TireRack.com

They have great information on there, and it agrees with 1010Tires on the 18x8.5" wheels.

 

Just make sure you maintain the overall diameter(27.3") when making tire width changes.It could throw off your speedo a bit or a lot.Here is a tire spec sheet from BF Goodrich for reference.Tire manufactuers differ in sizing but not that much.

http://www.bfgoodrichtires.com/specs...-a-kdw/22.html

 

I think maybe its a mistake. 255/45/18 is the widest the Rubber manufacturers association recommends, and that's who I would believe. Also the tire manufacturers say the same thing.

Big Customs specs don't agree with the tire manufacturers specs, lawsuit waiting to happen?

Example: From Goodyear's website
275/40ZR18 Approved Rim Width 9.0 - 11.0

From Big Customs on the same Goodyear tire.
275/40ZR18 18x8.5 to 18x10.5

Sure it will fit, but its not approved and not the the best for handling.
Even tho I am planning on going this route possibly, lol. But I will test mount a tire 1st.

I never seen anyone do that personally.
Why would they want more sidewall flex? That's whats going to happen.